Proposals to prevent homicides usually address "root causes," the historical circumstances that impel people to commit murder. Some causes are rooted immutably in human nature, while others stem from societal influences and can be changed over time. But police and prosecutors struggling to stop the killers who plague Baltimore City do not have the luxury of time. They need to use law enforcement tools that deter crime despite the persistence of root causes.

Incarcerating armed criminals and their accomplices is an obvious strategy to prevent murders. Long prison sentences incapacitate repeat offenders and deter others from following in their footsteps. Lengthy sentences also yield collateral benefits because the prospect of a substantial sentence reduction in return for cooperating persuades many criminals to disregard the "no snitching" culture and help police catch other violent offenders.


The challenge for law enforcement agencies is that it is not possible to convict most killers on murder charges. Almost 2,500 people were murdered in Baltimore City during the past decade, and nearly 5,000 victims suffered nonfatal gunshots. Most of the perpetrators will never be convicted of those crimes. And many of them will kill again. For example, one notorious Baltimore hit man was a suspect in at least two murders and 12 attempted murders before he was convicted on federal charges and sentenced to life in prison.

Baltimore is not unique. More than half of all murders nationwide do not result in murder convictions. Often there is no eyewitness who can identify the killer. Sometimes the only witnesses are accomplices or bystanders who are uncooperative, inconsistent or otherwise impeachable. Good police and prosecutors sometimes make a difference, but in many cases even exceptional investigators cannot obtain enough admissible evidence to prove a killer guilty beyond any reasonable doubt in a courtroom.

Violent crimes usually are related to ongoing illegal enterprises run by career criminals, however, so industrious police and prosecutors charge shooting suspects and their accomplices for other serious crimes, such as gun possession, drug distribution and conspiracy. When deciding what sentence to impose, the judge should consider the defendant's criminal record and other risk factors, and impose a longer sentence if there are indicia of recidivism.

Prosecuting violent criminals on lesser charges is a time-tested strategy. In 1929, gunmen working for Chicago mobster Al Capone attacked a rival gang in the infamous Valentine's Day Massacre. One victim was still alive when police arrived. Despite 14 bullet wounds, the bleeding gangster obstinately lied: "Nobody shot me." So Eliot Ness and his allies sent Capone to prison for a more readily provable crime — tax evasion.

Attorney General Robert Kennedy adopted a similar approach in 1961 when he counseled agents to fight organized crime with all available tools, even if it required prosecuting gangsters for minor offenses. In this century, after the attacks of Sept. 11, 2001, Attorney General John Ashcroft ordered prosecutors to disrupt terrorist plots by pursuing any lawful charges to put suspects behind bars before they carry out their murderous intentions.

Overwhelmed police agencies spend much of their time responding to emergency calls and investigating past crimes, but they convict only a fraction of the perpetrators. Proactive police and prosecutors identify violent repeat offenders, then they commit the resources needed to gather evidence of other prosecutable crimes. Targeting dangerous repeat offenders for proactive enforcement differs dramatically from a "zero tolerance" strategy of arresting random people for minor offenses. In one recent case, local and federal police and prosecutors worked together to secure a 20-year sentence for a recidivist murder suspect for the crime of illegally purchasing firearms. In another case, 26 defendants faced federal conspiracy charges for participating in a drug-dealing enterprise after their gangs were involved in a series of murders and shootings.

The recent spate of violence in Baltimore City threatens to reverse substantial crime reductions achieved over the past decade. The debate about what caused the lapse in deterrence will endure, as will efforts to remedy root causes and improve relationships between police officers and residents of crime-ridden neighborhoods. In the meantime, the crime surge can be suppressed if law enforcement agencies work together to secure lengthy sentences for armed felons, build proactive drug and conspiracy cases against members of gangs that foment violence, and prosecute dangerous offenders who violate probation or parole conditions. That approach worked in Baltimore from 2007 to 2014, when both shootings and arrests fell dramatically. It can work again.

Rod J. Rosenstein is U.S. attorney for Maryland; he can be reached at usamd.comments@usdoj.gov.